Jay Onrait and Dan O'Toole built a following in their native Canada for a nightly sportscast that featured the day's highlights along with all manner of quirky antics, like breaking into dance on set and using props ranging from a lint remover to a trombone.

Now, 21st Century Fox has enlisted the duo in its bid to take on ESPN, the U.S. sports-TV powerhouse. On Aug. 17, when the media company launches its new 24-hour cable channel, Fox Sports 1, Messrs. Onrait and O'Toole will have the difficult but crucial assignment of...